Wintergreen Korean boxwood is more tolerant of sunlight and alkaline soils than the common bxwood. In the spring, very small yellow flowers appear. They can go unnoticed, but they are very fragrant. Because of their shallow root systems, they do best with a thin (1- to 2-inch) layer of mulch. This cultivar is one of the most cold hardy. It also retains its dark green color better during the winter. This round evergreen shrub grows to about 4 feet in height with full sun to partial shade and moderate moisture conditions. The plant is frequently used in a hedge or border.